Bookbinding case, the covers of which consist of cardboard, which is doubled by folding it along the edges



- F. D'HUY BOOKBINDING CASE, E COVERS OF WHICH CONSIST OF CARDBOARD, WHICH IS DOUBLED BY FOLDING ALONG THE EDGES Filed 001;- 25, 1946 Patented Aug. 8, 1950 BOOKBIND ING CASE, 'THE COVERS OF WHICH CONSIST OF CARDBOARD, WHICH IS DOUBLED BY FOLDINGIT ALONG THE EDGES Franciscus Pieter DHuy, Overveen, Netherlands Application October 23, 1946, Serial No. 705,095 In the Netherlands October 26, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires October 26, 1963 3 Claims. (01. 281-29) The invention relates to a book-binding case, the covers of which consist of cardboard, preferably paperboard, which is doubled by folding it along the edges. In accordance with the invention, the cardboard is indented along the edges, the indentations afterwards-when the edges of the cardboard are folded over--doing duty as folding lines. In this way a binding case is obtained which, although it can be made of thin cardboard, still gives the impression-on account of the double edges-of solidity, and which actually is comparatively strong. A book-binding case of this kind at the same time possesses a certain amount of flexibility.

This property, however, cannot be reconciled with the character of the doubled edges of the case. As it is, it appears that, when trying to profit by the flexibility of the binding case, the stiffness of the material of the folding edge, which material has been folded over twice at approximately right angles, opposes itself to this, so that the case will break along the folding edge of the doubled portion. This will, of course, give the binding case an unsightly appearance and in consequence practice has shown that books bound in a cover of this type, are practically unsaleable on account of the very phenomenon mentioned above.

In the meantime it has been found, that, in acoordance with the invention this drawback can be obviated in a surprisingly simple way and that a binding case of the kind under discussion can be obtained, whereby the flexibility of the folding edge of the doubled edge portion is adapted to the flexibility of the remaining parts of the binding case.

For this purpose, in accordance with the invention the folding edges of the doubled edges of the covers are rounded off by an indentation, arranged parallel to the said folding edges, in such a Way that a cord or. cylinder-shaped folding edge is obtained, possessing a great flexibility in the longitudinal direction,

To elucidate the invention, an embodiment of the book-binding case will be described, with reference to the drawing.

In the drawings:

Fig. 1 is a perspective view of a portion of a binding case having an indentation therein;

Fig. 2 is a perspective view of the portion of the binding case shown in Fig. 1 with the fold shown at the indentation;

Fig. 3 is a perspective view of a corner of a binding case illustrating the breaking of the outer folded edge when a finished binding case is constructed as shown in Fig, 2;

Fig. 4 is a perspective view illustrating a portion of a binding case when constructed according to the invention with an indentation parallel and spaced from the folding edge;

Fig. 5 is a similar view with the indentation located at the interior of the binding case;

Fig. 6 is a perspective View of a corner of a binding case constructed according to the invention illustrating the flexibility thereof when constructed in accordance with the invention and Fig. 7 is a plan view of a complete book-binding case on a reduced scale.

Fig, 1, diagrammatically, shows a piece of cardboard, for instance paperboard, of which a binding case is to be manufactured. Preparatory to folding over the edge, the cardboard has been provided with an indentation l. folded along the said indentation I, for example in the direction of the arrow, according to Fig. 1, or in a direction opposite thereto, so that a double edge with a folding edge 2 (Fig. 2) at right angles, is obtained. Such a folding edge, which was customary until now, is so stiff, however, that, when bending a cover of the finished binding case, the outer folding edge will break, as is shown diagrammatically, near 3 and 4 of Fig. 3,

For this reason the folding edge obtained according to Fig. 2 is still further treated, which is done by providing an indentation parallel to and at a short distance from the folding edge. This indentation can be made on the outer side of the binding case, as shown near 5 in Fig. 4, or on the inner side of the binding case, as denoted by 6 in Fig. 5. In either case a cord or cylinder-shaped folding edge is obtained, the flexibility of which is similar to that of the remaining parts of the binding case, as is diagrammatically shown in Fig. 6. Consequently there need no longer be fear that, by putting undue strain on the flexibility of the binding case, a thing to which the construction of a case of the kind under discussion invites, damage will be done to the edges of the binding case covers.

The invention consequently makes it actually practicable to manufacture from inexpensive material, for instance paperboard, a flexible bookbinding case which combines a beautiful appearance with solidity.

In this connection it is observed that the indentation or indentations to be made, can be uninterrupted or interrupted, rectilinear or undulating, or zigzag. The application of the invention offers particular advantages in the case of a The cardboard is book-binding case, consisting of one single sheet of cardboard extending over the front cover the back portion and the back cover or consisting of material mainly composed of cardboard, although the application naturally is not confined to this.

I claim: a

1. A book-binding case of relatively thin cardboard and the like comprising covers having folded doubled edges and said edges being rounded by indentations located adjacent and parallel to said edges.

2. A book-binding case of relatively thin cardboard and the like comprising covers having folded double edges and said edges being rounded by indentations located adjacent and parallel to said edges at one side of said covers.

3. A book-binding case of relatively thin cardboard and the like comprising covers having 4 folded double edges and said edges being rounded by indentations located adjacent and parallel to said edges at both sides of said covers.

FRANCISCUS' PIETER D'I-IU'Y.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

